CVE-2026-64830: FFmpeg versions 2.1 through 8.1.2 contains a heap buffer overflow vulnerability in the VobSub subtitle demuxer

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HIGH 8.8UPGRADE

CVE-2026-64830 is a high-severity flaw (CVSS 8.8) affecting ffmpeg. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

FFmpeg versions 2.1 through 8.1.2 contains a heap buffer overflow vulnerability in the VobSub subtitle demuxer that allows attackers to corrupt adjacent heap memory by supplying a malicious .sub/.idx subtitle file declaring more distinct stream IDs than the fixed-size array bounds in libavformat/mpeg.c. Attackers can craft a subtitle file with excessive distinct stream IDs to trigger unbounded writes beyond the vobsub->q[] array boundary via ff_s

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.6% (top 50%)
CISA exploited list	No
Weakness	CWE-122
Published	2026-07-22
Last modified	2026-10-24

Publisher (CNA): VulnCheck · Vendor: ffmpeg

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-22 17:16 UTCPublished CVE record published
2026-10-24 15:10 UTCUpdated Record last modified

ffmpeg ffmpeg UPGRADE

Affected: >= 2.1 and <= 8.1.2

Fixed in: newer than 8.1.2

Safe to downgrade to: a release before 2.1

1. Check installed version

apt-cache policy ffmpeg || rpm -q ffmpeg || ffmpeg --version

2. UPGRADE to newer than 8.1.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade ffmpeg

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade ffmpeg

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 2.1 (Debian / Ubuntu)

apt-cache madison ffmpeg sudo apt install ffmpeg=<VERSION_BEFORE_2.1> sudo apt-mark hold ffmpeg

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list ffmpeg sudo dnf downgrade ffmpeg-<VERSION_BEFORE_2.1> sudo dnf versionlock add ffmpeg

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

Fedora 46 · sugar-abacus · FIXED · 61-18.fc46 · FEDORA-2026-b1e9de9204 · source

sudo dnf upgrade --advisory=FEDORA-2026-b1e9de9204

Fedora ELN · selinux-policy · FIXED · 45.23-1.eln159 · FEDORA-2026-3668c969a2 · source

sudo dnf upgrade --advisory=FEDORA-2026-3668c969a2

Ubuntu 20.04 · ffmpeg · FIXED · 7:4.2.7-0ubuntu0.1+esm16

sudo apt update && sudo apt install --only-upgrade ffmpeg dpkg --compare-versions "$(dpkg-query -W -f='${Version}' ffmpeg)" ge "7:4.2.7-0ubuntu0.1+esm16" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 22.04 · ffmpeg · FIXED · 7:4.4.2-0ubuntu0.22.04.1+esm15

sudo apt update && sudo apt install --only-upgrade ffmpeg dpkg --compare-versions "$(dpkg-query -W -f='${Version}' ffmpeg)" ge "7:4.4.2-0ubuntu0.22.04.1+esm15" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 24.04 · ffmpeg · FIXED · 7:6.1.1-3ubuntu5+esm13

sudo apt update && sudo apt install --only-upgrade ffmpeg dpkg --compare-versions "$(dpkg-query -W -f='${Version}' ffmpeg)" ge "7:6.1.1-3ubuntu5+esm13" && echo PATCHED || echo STILL-VULNERABLE

Debian 12 · ffmpeg · NO FIX YET

Debian 13 · ffmpeg · NO FIX YET

RHEL AI 3.0 for RHEL 9 · ffmpeg · FIXED · ffmpeg-6.1.6-9.el9ai

sudo dnf upgrade --advisory=RHSA-2026:74089 rpm -q ffmpeg

RHEL AI 3.3 for RHEL 9 · ffmpeg · FIXED · ffmpeg-6.1.6-9.el9ai

sudo dnf upgrade --advisory=RHSA-2026:67276 rpm -q ffmpeg

RHEL AI 3.4 for RHEL 9 · ffmpeg · FIXED · ffmpeg-6.1.6-9.el9ai

sudo dnf upgrade --advisory=RHSA-2026:67309 rpm -q ffmpeg

RHEL AI 3.5 for RHEL 9 · ffmpeg · FIXED · ffmpeg-6.1.6-9.el9ai

sudo dnf upgrade --advisory=RHSA-2026:67303 rpm -q ffmpeg

RHEL AI (RHEL AI) 3 · rhelai3/bootc-aws-cuda-rhel9 · NO FIX YET

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-64830?

ffmpeg: upgrade to newer than 8.1.2. Exact commands for each OS are on this page.

Is CVE-2026-64830 being exploited?

CVE-2026-64830 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-64830 affect?

CVE-2026-64830 affects ffmpeg. Severity is high (CVSS 8.8). FFmpeg versions 2.1 through 8.1.2 contains a heap buffer overflow vulnerability in the VobSub subtitle demuxer that allows attackers to corrupt adjacent heap memory by supplying a malicious .sub/.idx subtitle file declaring more distinct st

How urgent is CVE-2026-64830?

Priority 43/100. High severity

Software pages

FFmpeg vulnerabilities

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References

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